This invention relates generally to pipe fitting, and more particularly to an improved steam trap for removing condensate from steam lines.
The inverted bucket condensate traps of older systems were replaced by fixed-orifice devices, exemplified by U.S. Pat. 3,715,870 and 3,877,895, placed directly in a steam line, to separate water from steam, and let mainly the water only return to a boiler. The orifice size, even if specified correctly initially, may change over the years due to corrosion. By that time, the manuals may have been lost, so trial and error is necessary to find the correct orifice size. Too large or too small an orifice results in system inefficiency. The need to change orifices was addressed by U.S. Pat. No. 4,426,213, which provided a standard device into which various-sized inserts could be installed. While this represented an improvement over fixed orifice plates, it was necessary to disassemble the steam line in order to change inserts.
To avoid the need to separate the steam line in order to install a new fitting, it was later proposed to include a ball valve in the system, and place a removable jet or orifice in the ball. A plug was provided in the valve housing so that, with the valve temporarily closed, the jet could be removed and replaced, without having to break down the line. Even with this arrangement, though, some experimentation was required, since one could not see flow through the valve, and had to make measurements of some kind, with the system stabilized, in order to determine whether the proper sized jet had been installed at each location.
Since large systems may have such orifices at hundreds of locations, it is important to make fitting an orifice a simple matter requiring a minimum of experimentation and labor.